in the blast furnace, iron ore, cok

in the blast furnace, iron ore, coke, and limestone are fed in to the top of the furnace by a skip car. Hot air at 537 C is fed into the bottom of the furnace.After the coke is ignited, the hot air makes it burn vigorously.Carbon monoxide combines with the oxygen in the iron ore, reducing it to a spongy mass of iron.The iron,called pig iron,gradually seeps down through the charge and collects in the bottom of the furnace.The decomposed limestone acts as a flux and unites with the impurities to form a slag.Since the slag is lighter, it floats onthe top of the molten iron